Chapter 97 - Humerus

Question 1

1. The humeral head articulates with the _____ of the _____ to form the shoulder joint.

Answer 1

• Glenoid of the
• Scapula

Question 2

2. What are the 3 tubercles of the humerus? What structure do they form together?

Answer 2

• Greater, intermediate, lesser
• Together they form the intertubercular groove

Question 3

3. The bicipital bursa is located in the __________.

Answer 3

• Intertubercular groove of the humerus

Question 4

4. The biceps brachii tendon glides over what humeral structure?

Answer 4

• Bicipital bursa

Question 5

5. The biceps brachii is involved in what two articular motions?

Answer 5

• Flexion of the elbow
• Extension of the shoulder

Question 6

6. T/F – The collateral ligaments of the shoulder are located dorsomedial and dorsolateral on the joint.

Answer 6

• False, there are no collateral ligaments of the shoulder

Question 7

7. What structures make up the lateral stability of the shoulder? (2)

Answer 7

• Supraspinatus
• infraspinatus

Question 8

8. What 2 muscles insert laterally on the greater tubercle of the shoulder?

Answer 8

• Supraspinatus
• Infraspinatus

Question 9

9. Where do the infraspinatus and supraspinatus muscles insert?

Answer 9

• Onto the greater tubercle of the shoulder

Question 10

10. Where is the deltoid tuberosity located on the humerus?

Answer 10

• Craniolateral surface of the humerus at the junction of the proximal and middle thirds

Question 11

11. The deltoid tuberosity is the origin of what muscle?

Answer 11

• the deltoid muscle

Question 12

12. What are the action of the deltoid muscle? (2)

Answer 12

• Shoulder flexion
• Forelimb abduction

Question 13

13. What muscle inserts on the deltoid tuberosity? What is the action of this muscle?

Answer 13

• Superficial pectoral muscle
• Adductor of the forelimb

Question 14

14. What muscle occupies the muscolospiral groove to insert on the proximal radius?

Answer 14

• Brachialis muscle

Question 15

15. What muscle border is the radial nerve associated with?

Answer 15

• Caudal border of the brachialis

Question 16

16. The __________ muscle, which serves to advance the forelimb, inserts on the osseous ridge of the humerus that extends distally from the deltoid tuberosity

Answer 16

• Brachiocephalicus muscle

Question 17

17. What is the function of the brachiocephalicus muscle?

Answer 17

• Advances the forelimb, inserts on the ridge below the deltoid tuberosity

Question 18

18. The space between the distal humeral epicondyles forms the ____________.

Answer 18

• Olecranon fossa

Question 19

19. The shape of the humeral condyle allows for _____________. The shape of the olecranon fossa allows for ________________.

Answer 19

• Transfer of weight-bearing to the radial head
• Intimate articulation with the trochlear notch of the proximal ulna

Question 20

20. The brachial plexus leads to the ____________ artery and vein coursing from the medial aspect toward the shoulder. These give rise to the ____________ artery and vein at the level of the scapulohumeral joint.

Answer 20

• Axillary artery
• Brachial artery and vein

Question 21

23. Injury to the radial nerve proximal to the triceps branch results in _____________.

Answer 21

• Inability to bear weight on the limb

Question 21

21. The cephalic vein diverges from the _________ and continues distad in the grove between the _____________ and ________ muscles.

Answer 21

• External jugular vein
• Brachiocephalicus muscle
• Descending pectoral muscle

Question 22

22. The __________ nerve supplies all the extensor muscles distal to the shoulder. It runs with the _________ artery.

Answer 22

• Radial
• Brachial artery

Question 23

24. Injury to the radial nerve distal to the triceps branch results in horses who can _________ but cannot _________.

Answer 23

• Can extend the elbow and the carpus
• Extend the digit

Question 24

25. The ______, _________, and ________ nerves supply the flexors of the upper and lower limb.

Answer 24

- Musculocutaneous - Median - Ulnar

Question 25

26. The _____ nerve supplies the coracopracialis and biceps brachii muscles

Answer 25

- Musculocutaneous nerve

Question 26

27. The _______ nerve courses along the cranial border of the brachial artery before moving to the caudal margin of the artery at the level of the elbow

Answer 26

- Median

Question 27

28. The_____ nerve courses alongthe caudal border of the brachial artery before passing over the medial epicondyle of the humerus and entering the forearm.

Answer 27

- Ulnar

Question 28

29. Why is injury to either the ulnar or median nerve alone unlikely to significantly effect gait or limb function?

Answer 28

- The muscles have shared innervation from both nerves